Multi-speed transmissions with a stationary planetary member

ABSTRACT

The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and at least one reverse speed ratio. The transmission family members include three planetary gear sets having six torque-transmitting mechanisms and two fixed interconnections. Also, one planetary gear member is continuously connected with the transmission housing. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with at least one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, the fixed interconnections, the input shaft, the output shaft, and the transmission housing, and are operated in combinations of two to establish at least seven forward speed ratios and at least one reverse speed ratio.

TECHNICAL FIELD

[0001] The present invention relates to a family of power transmissionshaving three planetary gear sets that are controlled by sixtorque-transmitting devices to provide at least seven forward speedratios and at least one reverse speed ratio.

BACKGROUND OF THE INVENTION

[0002] Passenger vehicles include a powertrain that is comprised of anengine, multi-speed transmission, and a differential or final drive. Themulti-speed transmission increases the overall operating range of thevehicle by permitting the engine to operate through its torque range anumber of times. The number of forward speed ratios that are availablein the transmission determines the number of times the engine torquerange is repeated. Early automatic transmissions had two speed ranges.This severely limited the overall speed range of the vehicle andtherefore required a relatively large engine that could produce a widespeed and torque range. This resulted in the engine operating at aspecific fuel consumption point during cruising, other than the mostefficient point. Therefore, manually-shifted countershaft transmissionswere the most popular.

[0003] With the advent of three- and four-speed automatic transmissions,the automatic shifting (planetary gear) transmission increased inpopularity with the motoring public. These transmissions improved theoperating performance and fuel economy of the vehicle. The increasednumber of speed ratios reduces the step size between ratios andtherefore improves the shift quality of the transmission by making theratio interchanges substantially imperceptible to the operator undernormal vehicle acceleration.

[0004] It has been suggested that the number of forward speed ratios beincreased to six or more. Six-speed transmissions are disclosed in U.S.Pat. No. 4,070,927 issued to Polak on Jan. 31, 1978; U.S. Pat. No.6,071,208 issued to Koivunen on Jun. 6, 2000; U.S. Pat. No. 5,106,352issued to Lepelletier on Apr. 21, 1992; and U.S. Pat. No. 5,599,251issued to Beim and McCarrick on Feb. 4, 1997.

[0005] Six-speed transmissions offer several advantages over four- andfive-speed transmissions, including improved vehicle acceleration andimproved fuel economy. While many trucks employ power transmissions,such as Polak, having six or more forward gear ratios, passenger carsare still manufactured with three- and four-speed automatictransmissions and relatively few five or six-speed devices due to thesize and complexity of these transmissions. The Polak transmissionprovides six forward speed ratios with three planetary gear sets, twoclutches, and three brakes. The Koivunen and Beim patents utilize sixtorque-transmitting devices including four brakes and two clutches toestablish six forward speed ratios and a reverse ratio. The Lepelletierpatent employs three planetary gear sets, three clutches and two brakesto provide six forward speeds. One of the planetary gear sets ispositioned and operated to establish two fixed speed input members forthe remaining two planetary gear sets.

[0006] Seven-speed transmissions are disclosed in U.S. Pat. No.4,709,594 to Maeda; U.S. Pat. No. 6,053,839 to Baldwin et. al.; and U.S.Pat. No. 6,083,135 to Baldwin et. al. Seven- and eight-speedtransmissions provide further improvements in acceleration and fueleconomy over six-speed transmissions. However, like the six-speedtransmissions discussed above, the development of seven- and eight-speedtransmissions has been precluded because of complexity, size and cost.

SUMMARY OF THE INVENTION

[0007] It is an object of the present invention to provide an improvedfamily of transmissions having three planetary gear sets controlled toprovide at least seven forward speed ratios and at least one reversespeed ratio.

[0008] In one aspect of the present invention, the family oftransmissions has three planetary gear sets, each of which includes afirst, second and third member, which members may comprise a sun gear, aring gear, or a planet carrier assembly member.

[0009] In referring to the first, second and third gear sets in thisdescription and in the claims, these sets may be counted “first” to“third” in any order in the drawings (i.e., left to right, right toleft, etc.).

[0010] In another aspect of the present invention, each of the planetarygear sets may be of the single pinion-type or of the double pinion-type.

[0011] In yet another aspect of the present invention, the first memberof the first planetary gear set is continuously interconnected to thefirst member of the second planetary gear set through a firstinterconnecting member.

[0012] In yet another aspect of the present invention, the second memberof the first planetary gear set is continuously interconnected with thesecond member of the second planetary gear set through a secondinterconnecting member.

[0013] In yet a further aspect of the present invention, the firstmember of the third planetary gear set is continuously interconnectedwith a transmission housing.

[0014] In yet a further aspect of the invention, each family memberincorporates an input shaft which is continuously connected with amember of the planetary gear sets and an output shaft which iscontinuously connected with another member of the planetary gear sets.

[0015] In still a further aspect of the invention, a firsttorque-transmitting mechanism, such as a clutch, selectivelyinterconnects a member of the first planetary gear set with the inputshaft, output shaft, or a member of the second or third planetary gearset.

[0016] In another aspect of the invention, a second torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thesecond planetary gear set with the input shaft, the output shaft, or amember of the first or third planetary gear set.

[0017] In a still further aspect of the invention, a thirdtorque-transmitting mechanism, such as a clutch, selectivelyinterconnects a member of the third planetary gear set with the inputshaft, the output shaft, or a member of the first or second planetarygear set.

[0018] In a still further aspect of the invention, a fourthtorque-transmitting mechanism, such as a clutch, selectivelyinterconnects a member of the first, second or third planetary gear setwith another member of the first, second or third planetary gear set.

[0019] In a still further aspect of the invention, a fifthtorque-transmitting mechanism, such as a clutch, selectivelyinterconnects a member of the second or third planetary gear set withanother member of the first, second or third planetary gear set.Alternatively, the fifth torque-transmitting mechanism, such as a brake,selectively interconnects a member of the first, second or thirdplanetary gear set with the transmission housing.

[0020] In still another aspect of the invention, a sixthtorque-transmitting mechanism, such as a clutch, selectivelyinterconnects a member of the first, second or third planetary gear setor the first or second interconnecting member with another member of thefirst, second or third planetary gear set. Alternatively, the sixthtorque transmitting mechanism, such as a brake, selectively connects amember of the first, second or third planetary gear set with thetransmission housing.

[0021] In still another aspect of the invention, the sixtorque-transmitting mechanisms are selectively engageable incombinations of two to yield at least seven forward speed ratios and atleast one reverse speed ratio.

[0022] The above object and other objects, features, and advantages ofthe present invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]FIG. 1a is a schematic representation of a powertrain including aplanetary transmission incorporating a family member of the presentinvention;

[0024]FIG. 1b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 1a;

[0025]FIG. 2a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0026]FIG. 2b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 2a;

[0027]FIG. 3a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0028]FIG. 3b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 3a;

[0029]FIG. 4a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0030]FIG. 4b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 4a;

[0031]FIG. 5a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0032]FIG. 5b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 5a;

[0033]FIG. 6a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0034]FIG. 6b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 6a;

[0035]FIG. 7a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0036]FIG. 7b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 7a;

[0037]FIG. 8a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0038]FIG. 8b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 8a;

[0039]FIG. 9a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0040]FIG. 9b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 9a;

[0041]FIG. 10a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0042]FIG. 10b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 10a;

[0043]FIG. 11a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0044]FIG. 11b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 11a;

[0045]FIG. 12a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

[0046]FIG. 12b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 12a;

[0047]FIG. 13a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention; and

[0048]FIG. 13b is a truth table and chart depicting some of theoperating characteristics of the powertrain shown in FIG. 13a.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0049] Referring to the drawings, wherein like characters represent thesame or corresponding parts throughout the several views, there is shownin FIG. 1a a powertrain 10 having a conventional engine and torqueconverter 12, a planetary transmission 14, and a conventional finaldrive mechanism 16.

[0050] The planetary transmission 14 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 18, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 18 includes three planetary gear sets 20, 30 and 40.

[0051] The planetary gear set 20 includes a sun gear member 22, a ringgear member 24, and a planet carrier assembly 26. The planet carrierassembly 26 includes a plurality of pinion gears 27 rotatably mounted ona carrier member 29 and disposed in meshing relationship with both thesun gear member 22 and the ring gear member 24.

[0052] The planetary gear set 30 includes a sun gear member 32, a ringgear member 34, and a planet carrier assembly member 36. The planetcarrier assembly member 36 includes a plurality of pinion gears 37rotatably mounted on a carrier member 39 and disposed in meshingrelationship with both the sun gear member 32 and the ring gear member34.

[0053] The planetary gear set 40 includes a sun gear member 42, a ringgear member 44, and a planet carrier assembly member 46. The planetcarrier assembly member 46 includes a plurality of pinion gears 47rotatably mounted on a carrier member 49 and disposed in meshingrelationship with both the sun gear member 42 and the ring gear member44.

[0054] The planetary gear arrangement also includes sixtorque-transmitting mechanisms 50, 52, 54, 56, 58 and 59. Thetorque-transmitting mechanisms 50, 52, 54 and 56 are of therotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 58 and 59 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

[0055] The input shaft 17 is continuously connect with the sun gearmember 42, and the output shaft 19 is continuously connected with theplanet carrier assembly member 26. The planet carrier assembly member 46is continuously connected with the transmission housing 60. The ringgear member 24 is continuously connected with the planet carrierassembly member 36 through the interconnecting member 70. The planetcarrier assembly member 26 is continuously connected with the ring gearmember 34 through the interconnecting member 72.

[0056] The planet carrier assembly member 36 is selectively connectablewith the sun gear member 42 through the clutch 50. The sun gear member22 is selectively connectable with the sun gear member 42 through theclutch 52. The sun gear member 32 is selectively connectable with thesun gear member 42 through the clutch 54. The sun gear member 32 isselectively connectable with the ring gear member 44 through the clutch56. The ring gear member 24 is selectively connectable with thetransmission housing 60 through the brake 58. The sun gear member 32 isselectively connectable with the transmission housing 60 through thebrake 59.

[0057] As shown in FIG. 1b, and in particular the truth table disclosedtherein, the torque-transmitting mechanisms are selectively engaged incombinations of two to provide seven forward speed ratios and a reversespeed ratio. It should also be noted in the truth table that thetorque-transmitting mechanism 58 remains engaged through a neutralcondition, thereby simplifying the forward/reverse interchange.

[0058] The reverse speed ratio is established with the engagement of theclutch 54 and the brake 58. The clutch 54 connects the sun gear member32 to the sun gear member 42. The brake 58 connects the ring gear member24 to the transmission housing 60. The planet carrier assembly member 26rotates at the same speed as the ring gear member 34 and the outputshaft 19. The ring gear member 24 and planet carrier assembly member 36do not rotate. The sun gear members 32, 42 rotate at the same speed asthe input shaft 17. The ring gear member 34 rotates at a speeddetermined from the speed of the sun gear member 32 and the ringgear/sun gear tooth ratio of the planetary gear set 30. The planetcarrier assembly member 46 does not rotate. The numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 30.

[0059] The first forward speed ratio is established with the engagementof the clutch 56 and the brake 58. The clutch 56 connects the sun gearmember 32 to the ring gear member 44. The brake 58 connects the ringgear member 24 to the transmission housing 60. The planet carrierassembly member 26 and ring gear member 34 rotate at the same speed asthe output shaft 19. The ring gear member 24 and the planet carrierassembly member 36 do not rotate. The sun gear member 32 rotates at thesame speed as the ring gear member 44. The ring gear member 34 rotatesat a speed determined from the speed of the sun gear member 32 and thering gear/sun gear tooth ratio of the planetary gear set 30. The planetcarrier assembly member 46 does not rotate. The sun gear member 42rotates at a same speed as the input shaft 17. The ring gear member 44rotates at a speed determined from the speed of the sun gear member 42and the ring gear/sun gear tooth ratio of the planetary gear set 40. Thenumerical value of the first forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 30 and40.

[0060] The second forward speed ratio is established with the engagementof the clutch 52 and the brake 58. The clutch 52 connects the sun gearmember 22 to the sun gear member 42. The brake 58 connects the ring gearmember 24 to the transmission housing 60. The planet carrier assemblymember 26 rotates at the same speed as the ring gear member 34 and theoutput shaft 19. The ring gear member 24 and planet carrier assemblymember 36 do not rotate. The sun gear member 22 rotates at the samespeed as the sun gear member 42 and the input shaft 17. The planetcarrier assembly member 26, and therefore the output shaft 19, rotatesat a speed determined from the speed of the sun gear member 22 and thering gear/sun gear tooth ratio of the planetary gear set 20. The planetcarrier assembly member 46 does not rotate. The numerical value of thesecond forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 20.

[0061] The third forward speed ratio is established with the engagementof the clutches 52 and 56. The clutch 52 connects the sun gear member 22to the sun gear member 42. The clutch 56 connects the sun gear member 32to the ring gear member 44. The planet carrier assembly member 26rotates at the same speed as the ring gear member 34 and the outputshaft 19. The ring gear member 24 rotates at the same speed as theplanet carrier assembly member 36. The sun gear members 22, 42 rotatesat the same speed as the input shaft 17. The planet carrier assemblymember 26, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the ring gear member 24, the speed of thesun gear member 22, and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The sun gear member 32 rotates at the same speedas the ring gear member 44. The planet carrier assembly member 36rotates at a speed determined from the speed of the ring gear member 34,the speed of the sun gear member 32, and the ring gear/sun gear toothratio of the planetary gear set 30. The planet carrier assembly member46 does not rotate. The ring gear member 44 rotates at a speeddetermined from the speed of the sun gear member 42 and the ringgear/sun gear tooth ratio of the planetary gear set 40. The numericalvalue of the third forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 20, 30 and 40.

[0062] The fourth forward speed ratio is established with the engagementof the clutch 52 and the brake 59. The clutch 52 connects the sun gearmember 22 to the sun gear member 42. The brake 59 connects the sun gearmember 32 to the transmission housing 60. The planet carrier assemblymember 26 and ring gear member 34 rotate at the same speed as the outputshaft 19. The ring gear member 24 rotates at the same speed as theplanet carrier assembly member 36. The sun gear members 22,42 rotate atthe same speed as the input shaft 17. The planet carrier assembly member26, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the ring gear member 24, the speed of the sun gearmember 22, and the ring gear/sun gear tooth ratio of the planetary gearset 20. The sun gear member 32 does not rotate. The planet carrierassembly member 36 rotates at a speed determined from the speed of thering gear member 34 and the ring gear/sun gear tooth ratio of theplanetary gear set 30. The planet carrier assembly member 46 does notrotate. The numerical value of the fourth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 20 and 30.

[0063] The fifth forward speed ratio is established with the engagementof the clutches 50 and 52. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefifth forward speed ratio is 1.

[0064] The sixth forward speed ratio is established with the engagementof the clutch 50 and the brake 59. The clutch 50 connects the planetcarrier assembly member 36 to the sun gear member 42. The brake 59connects the sun gear member 32 to the transmission housing 60. The ringgear member 24, planet carrier assembly member 36, and sun gear member42 rotate at the same speed as the input shaft 17. The planet carrierassembly member 26 and ring gear member 34 rotate at the same speed asthe output shaft 19. The sun gear member 32 does not rotate. The ringgear member 34, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the planet carrier assembly member 36, andthe ring gear/sun gear tooth ratio of the planetary gear set 30. Theplanet carrier assembly member 46 does not rotate. The numerical valueof the sixth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 30.

[0065] The seventh forward speed ratio is established with theengagement of the clutches 50 and the 56. The clutch 50 connects theplanet carrier assembly member 36 to the sun gear member 42. The clutch56 connects the sun gear member 32 to the ring gear member 44. Theplanet carrier assembly member 26 and ring gear member 34 rotate at thesame speed as the output shaft 19. The ring gear member 34, planetcarrier assembly member 36, and sun gear member 42 rotate at the samespeed as the input shaft 17. The sun gear member 32 rotates at the samespeed as the ring gear member 44. The planet carrier assembly member 36rotates at a speed determined from the speed of the ring gear member 34,the speed of the sun gear member 32, and the gear/sun gear tooth ratioof the planetary gear set 30. The planet carrier assembly member 46 doesnot rotate. The ring gear member 44 rotates at a speed determined fromthe speed of the sun gear member 42, and the ring gear/sun gear toothratio of the planetary gear set 40. The numerical value of the seventhforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 30 and 40.

[0066] As set forth above, the engagement schedule for thetorque-transmitting mechanisms is shown in the truth table of FIG. 1b.This truth table also provides an example of speed ratios that areavailable utilizing the ring gear/sun gear tooth ratios given by way ofexample in FIG. 1b. The R1/S1 value is the tooth ratio of the planetarygear set 20; the R2/S2 value is the tooth ratio of the planetary gearset 30; and the R3/S3 value is the tooth ratio of the planetary gear set40. Also, the chart of FIG. 1b describes the ratio steps that areattained utilizing the sample of tooth ratios given. For example, thestep ratio between the first and second forward speed ratios is 1.79,while the step ratio between the reverse and first forward ratio is0.59. It can also be readily determined from the truth table of FIG. 1bthat all of the single step forward ratio interchanges are of the singletransition variety, as are the double step forward ratio interchanges.

[0067]FIG. 2a shows a powertrain 110 having a conventional engine andtorque converter 12, a planetary transmission 114, and a conventionalfinal drive mechanism 16.

[0068] The planetary transmission 114 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 118, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 118 includes three planetary gear sets 120, 130 and 140.

[0069] The planetary gear set 120 includes a sun gear member 122, a ringgear member 124, and a planet carrier assembly 126. The planet carrierassembly 126 includes a plurality of pinion gears 127 rotatably mountedon a carrier member 129 and disposed in meshing relationship with boththe sun gear member 122 and the ring gear member 124.

[0070] The planetary gear set 130 includes a sun gear member 132, a ringgear member 134, and a planet carrier assembly member 136. The planetcarrier assembly member 136 includes a plurality of pinion gears 137rotatably mounted on a carrier member 139 and disposed in meshingrelationship with both the sun gear member 132 and the ring gear member134.

[0071] The planetary gear set 140 includes a sun gear member 142, a ringgear member 144, and a planet carrier assembly member 146. The planetcarrier assembly member 146 includes a plurality of pinion gears 147rotatably mounted on a carrier member 149 and disposed in meshingrelationship with both the sun gear member 142 and the ring gear member144.

[0072] The planetary gear arrangement 118 also includes sixtorque-transmitting mechanisms 150, 152, 154, 156, 158 and 159. Thetorque-transmitting mechanisms 150, 152, 154 and 156 are of therotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 158 and 159 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

[0073] The input shaft 17 is continuously connected with the planetcarrier assembly member 126, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 146. The sun gearmember 142 is continuously connected with the transmission housing 160.The sun gear member 122 is continuously connected with the planetcarrier assembly member 136 through the interconnecting member 170. Thering gear member 124 is continuously connected with the sun gear member132 through the interconnecting member 172.

[0074] The ring gear member 134 is selectively connectable with theplanet carrier assembly 136 through the clutch 150. The planet carrierassembly member 136 is selectively connectable with the ring gear member144 through the clutch 152. The sun gear member 132 is selectivelyconnectable with the planet carrier assembly member 146 through theclutch 154. The ring gear member 134 is selectively connectable with theplanet carrier assembly member 146 through the clutch 156. The planetcarrier assembly member 136 is selectively connectable with thetransmission housing 160 through the brake 158. The ring gear member 134is selectively connectable with the transmission housing 160 through thebrake 159.

[0075] The truth table of FIG. 2b describes the engagement sequenceutilized to provide seven forward speed ratios and a reverse speed ratioin the planetary gear arrangement 118 shown in FIG. 2a.

[0076] The reverse speed ratio is established with the engagement of theclutch 156 and brake 158. The clutch 156 connects the ring gear member134 to the planet carrier assembly member 146. The brake 158 connectsthe planet carrier assembly member 136 to the transmission housing 160.The planet carrier assembly member 126 rotates at the same speed as theinput shaft 17. The ring gear member 124 rotates at the same speed asthe sun gear member 132. The sun gear member 122 and planet carrierassembly member 136 do not rotate. The ring gear member 124 rotates at aspeed determined from the speed of the planet carrier assembly member126, and the ring gear/sun gear tooth ratio of the planetary gear set120. The ring gear member 134 and planet carrier assembly member 146rotate at the same speed as the output shaft 19. The ring gear member134 rotates at a speed determined from the speed of the sun gear member132, and the ring gear/sun gear tooth ratio of the planetary gear set130. The sun gear member 142 does not rotate. The numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 120 and 130.

[0077] The first forward speed ratio is established with the engagementof the clutch 152 and brake 159. The clutch 152 connects the planetcarrier assembly member 136 to the ring gear member 144. The brake 159connects the ring gear member 134 to the transmission housing 160. Theplanet carrier assembly member 126 rotates at the same speed as theinput shaft 17. The ring gear member 124 rotates at the same speed asthe sun gear member 132. The sun gear member 122 rotates at the samespeed as the planet carrier assembly member 136 and the ring gear member144. The ring gear member 124 rotates at a speed determined from thespeed of the planet carrier assembly member 126, the speed of the sungear member 122, and the ring gear/sun gear tooth ratio of the planetarygear set 120. The ring gear member 134 does not rotate. The planetcarrier assembly member 136 rotates at a speed determined from the speedof the sun gear member 132 and the ring gear/sun gear tooth ratio of theplanetary gear set 130. The sun gear member 142 does not rotate. Theplanet carrier assembly member 146 rotates at the same speed as theoutput shaft 19. The planet carrier assembly member 146, and thereforethe output shaft 19, rotates at a speed determined from the speed of thering gear member 144 and the ring gear/sun gear tooth ratio of theplanetary gear set 140. The numerical value of the first forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 120, 130 and 140.

[0078] The second forward speed ratio is established with the engagementof the clutches 152 and 156. The clutch 152 connects the planet carrierassembly member 136 to the ring gear member 144. The clutch 156 connectsthe ring gear member 134 to the planet carrier assembly member 146. Theplanet carrier assembly member 126 rotates at the same speed as theinput shaft 17. The ring gear member 124 rotates at the same speed asthe sun gear member 132. The sun gear member 122 rotates at the samespeed as the planet carrier assembly member 136 and the ring gear member144. The ring gear member 124 rotates at a speed determined from thespeed of the planet carrier assembly member 126, the speed of the sungear member 122, and the ring gear/sun gear tooth ratio of the planetarygear set 120. The ring gear member 134 and planet carrier assemblymember 146 rotate at the same speed as the output shaft 19. The planetcarrier assembly member 136 rotates at a speed determined from the speedof the ring gear member 134, the speed of the sun gear member 132, andthe ring gear/sun gear tooth ratio of the planetary gear set 130. Thesun gear member 142 does not rotate. The planet carrier assembly member146, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the ring gear member 144, and the ring gear/sun geartooth ratio of the planetary gear set 140. The numerical value of thesecond forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 120, 130 and 140.

[0079] The third forward speed ratio is established with the engagementof the clutches 150 and 152. The clutch 150 connects the ring gearmember 134 to the planet carrier assembly member 136. The clutch 152connects the planet carrier assembly member 136 to the ring gear member144. The planet carrier assembly member 126 rotates at the same speed asthe input shaft 17. The ring gear member 124 rotates at the same speedas the sun gear member 132. The sun gear member 122 rotates at the samespeed as the planet carrier assembly member 136, and the ring gearmembers 134,144. The sun gear member 142 does not rotate. The planetcarrier assembly member 146 rotates at the same speed as the outputshaft 19. The planet carrier assembly member 146, and therefore theoutput shaft 19, rotates at a speed determined from the speed of thering gear member 144, and the ring gear/sun gear tooth ratio of theplanetary gear set 140. The numerical value of the third forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 140.

[0080] The fourth forward speed ratio is established with the engagementof the clutches 152 and 154. The clutch 152 connects the planet carrierassembly member 136 to the ring gear member 144. The clutch 154 connectsthe sun gear member 132 to the planet carrier assembly member 146. Theplanet carrier assembly member 126 rotates at the same speed as theinput shaft 17. The ring gear member 124 rotates at the same speed asthe sun gear member 132, the planet carrier assembly member 146, and theoutput shaft 19. The sun gear member 122 rotates at the same speed asthe planet carrier assembly member 136 and the ring gear member 144. Thering gear member 124 rotates at a speed determined from the speed of theplanet carrier assembly member 126, the speed of the sun gear member122, and the ring gear/sun gear tooth ratio of the planetary gear set120. The sun gear member 142 does not rotate. The planet carrierassembly member 146, and therefore the output shaft 19, rotates at aspeed determined from the speed of the ring gear member 144 and the ringgear/sun gear tooth ratio of the planetary gear set 140. The numericalvalue of the fourth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 120 and 140.

[0081] The fifth forward speed ratio is established with the engagementof the clutches 154 and 156. In this configuration, the input shaft 17is directly connected to the output shaft 19. The numerical value of thefifth forward speed ratio is 1.

[0082] The sixth forward speed ratio is established with the engagementof the clutch 154 and the brake 159. The clutch 154 connects the sungear member 132 to the planet carrier assembly member 146. The brake 159connects the ring gear member 134 to the transmission housing 160. Theplanet carrier assembly member 126 rotates at the same speed as theinput shaft 17. The ring gear member 124 rotates at the same speed asthe sun gear member 132, the planet carrier assembly member 146, and theoutput shaft 19. The sun gear member 122 rotates at the same speed asthe planet carrier assembly member 136. The ring gear member 124 rotatesat a speed determined from the speed of the planet carrier assemblymember 126, the speed of the sun gear member 122, and the ring gear/sungear tooth ratio of the planetary gear set 120. The ring gear member 134does not rotate. The planet carrier assembly member 136 rotates at aspeed determined from the speed of the sun gear member 132 and the ringgear/sun gear tooth ratio of the planetary gear set 130. The sun gearmember 142 does not rotate. The numerical value of the sixth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 120 and 130.

[0083] The seventh forward speed ratio is established with theengagement of the clutch 154 and the brake 158. The clutch 154 connectsthe sun gear member 132 to the planet carrier assembly member 146. Thebrake 158 connects the planet carrier assembly member 136 to thetransmission housing 160. The planet carrier assembly member 126 rotatesat the same speed as the input shaft 17. The ring gear member 124, sungear member 132, and planet carrier assembly member 146 rotate at thesame speed as the output shaft 19. The sun gear member 122, planetcarrier assembly member 136, and sun gear member 142 do not rotate. Thering gear member 124 rotates at a speed determined from the speed of theplanet carrier assembly member 126 and the ring gear/sun gear toothratio of the planetary gear set 120. The numerical value of the seventhforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear set 120.

[0084] As set forth above, the truth table of FIG. 2b describes theengagement sequence of the torque-transmitting mechanisms utilized toprovide a reverse drive ratio and seven forward speed ratios. It can bereadily determined from the truth table that all of the single stepforward interchanges are of the single transition type. The truth tablealso provides an example of the ratios that can be attained with thefamily members shown in FIG. 2a utilizing the sample tooth ratios givenin FIG. 2b. The R1/S1 value is the tooth ratio of the planetary gear set120; the R2/S2 value is the tooth ratio of the planetary gear set 130;and the R3/S3 value is the tooth ratio of the planetary gear set 140.Also shown in FIG. 2b are the ratio steps between single step ratios inthe forward direction as well as the reverse to first ratio step ratio.For example, the first to second step ratio is 1.7.

[0085] Turning to FIG. 3a, a powertrain 210 includes the engine andtorque converter 12, a planetary transmission 214, and a final drivemechanism 16. The planetary transmission 214 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 218, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 218 includes three planetary gear sets 220, 230 and 240.

[0086] The planetary gear set 220 includes a sun gear member 222, a ringgear member 224, and a planet carrier assembly 226. The planet carrierassembly 226 includes a plurality of pinion gears 227 rotatably mountedon a carrier member 229 and disposed in meshing relationship with boththe sun gear member 222 and the ring gear member 224.

[0087] The planetary gear set 230 includes a sun gear member 232, a ringgear member 234, and a planet carrier assembly member 236. The planetcarrier assembly member 236 includes a plurality of pinion gears 237rotatably mounted on a carrier member 239 and disposed in meshingrelationship with both the sun gear member 232 and the ring gear member234.

[0088] The planetary gear set 240 includes a sun gear member 242, a ringgear member 244, and a planet carrier assembly member 246. The planetcarrier assembly member 246 includes a plurality of pinion gears 247rotatably mounted on a carrier member 249 and disposed in meshingrelationship with both the sun gear member 242 and the ring gear member244.

[0089] The planetary gear arrangement 218 also includes sixtorque-transmitting mechanisms 250, 252, 254, 256, 258 and 259. Thetorque-transmitting mechanisms 250, 252, 254 and 256 are of the rotatingtype torque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanisms 258 and 259 are stationary typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

[0090] The input shaft 17 is continuously connect with the planetcarrier assembly member 226, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 246. The sun gearmember 242 is continuously connected with the transmission housing 260.The sun gear member 222 is continuously connected with the planetcarrier assembly member 236 through the interconnecting member 270. Thering gear member 224 is continuously connected with the sun gear member232 through the interconnecting member 272.

[0091] The planet carrier assembly member 236 is selectively connectablewith the sun gear member 232 through the clutch 250. The planet carrierassembly member 236 is selectively connectable with the ring gear member244 through the clutch 252. The sun gear member 232 is selectivelyconnectable with the planet carrier assembly member 246 through theclutch 254. The ring gear member 234 is selectively connectable with theplanet carrier assembly member 246 through the clutch 256. The planetcarrier assembly member 236 is selectively connectable with thetransmission housing 260 through the brake 258. The ring gear member 234is selectively connectable with the transmission housing 260 through thebrake 259.

[0092] As shown in the truth table in FIG. 3b, the torque-transmittingmechanisms are engaged in combinations of two to establish seven forwardspeed ratios and one reverse ratio.

[0093] The reverse speed ratio is established with the engagement of theclutch 256 and brake 258. The clutch 256 connects the ring gear member234 to the planet carrier assembly member 246. The brake 258 connectsthe planet carrier assembly member 236 to the transmission housing 260.The planet carrier assembly member 226 rotates at the same speed as theinput shaft 17. The ring gear member 224 rotates at the same speed asthe sun gear member 232. The sun gear member 222 and planet carrierassembly member 236 do not rotate. The ring gear member 224 rotates at aspeed determined from the speed of the planet carrier assembly member226 and the ring gear/sun gear tooth ratio of the planetary gear set220. The ring gear member 234 and planet carrier assembly member 246rotate at the same speed as the output shaft 19. The ring gear member234 rotates at a speed determined from the speed of the sun gear member232, and the ring gear/sun gear tooth ratio of the planetary gear set230. The sun gear member 242 does not rotate. The numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 220 and 230.

[0094] The first forward speed ratio is established with the engagementof the clutch 252 and brake 259. The clutch 252 connects the planetcarrier assembly member 236 to the ring gear member 244. The brake 259connects the ring gear member 234 to the transmission housing 260. Theplanet carrier assembly member 226 rotates at the same speed as theinput shaft 17. The ring gear member 224 rotates at the same speed asthe sun gear member 232. The sun gear member 222 rotates at the samespeed as the planet carrier assembly member 236 and the ring gear member244. The ring gear member 224 rotates at a speed determined from thespeed of the planet carrier assembly member 226, the speed of the sungear member 222, and the ring gear/sun gear tooth ratio of the planetarygear set 220. The ring gear member 234 does not rotate. The planetcarrier assembly member 236 rotates at a speed determined from the speedof the sun gear member 232 and the ring gear/sun gear tooth ratio of theplanetary gear set 230. The sun gear member 242 does not rotate. Theplanet carrier assembly member 246 rotates at the same speed as theoutput shaft 19. The planet carrier assembly member 246, and thereforethe output shaft 19, rotates at a speed determined from the speed of thering gear member 244 and the ring gear/sun gear tooth ratio of theplanetary gear set 240. The numerical value of the first forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 220, 230 and 240.

[0095] The second forward speed ratio is established with the engagementof the clutches 252 and 256. The clutch 252 connects the planet carrierassembly member 236 to the ring gear member 244. The clutch 256 connectsthe ring gear member 234 to the planet carrier assembly member 246. Theplanet carrier assembly member 226 rotates at the same speed as theinput shaft 17. The ring gear member 224 rotates at the same speed asthe sun gear member 232. The sun gear member 222 rotates at the samespeed as the planet carrier assembly member 236 and ring gear member244. The ring gear member 224 rotates at a speed determined from thespeed of the planet carrier assembly member 226, the speed of the sungear member 222, and the ring gear/sun gear tooth ratio of the planetarygear set 220. The ring gear member 234 rotates at the same speed as theplanet carrier assembly member 246 and the output shaft 19. The planetcarrier assembly member 236 rotates at a speed determined from the speedof the ring gear member 234, the speed of the sun gear member 232, andthe ring gear/sun gear tooth ratio of the planetary gear set 230. Thesun gear member 242 does not rotate. The planet carrier assembly member246, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the ring gear member 244 and the ring gear/sun geartooth ratio of the planetary gear set 240. The numerical value of thesecond forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 220, 230 and 240.

[0096] The third forward speed ratio is established with the engagementof the clutches 250 and 252. The clutch 250 connects the planet carrierassembly member 236 to the sun gear member 232. The clutch 252 connectsthe planet carrier assembly member 236 to the ring gear member 244. Theplanet carrier assembly member 226 rotates at the same speed as theinput shaft 17. The ring gear member 224 rotates at the same speed asthe sun gear member 222, the sun gear member 232, the planet carrierassembly member 236, and the ring gear member 244. The planet carrierassembly member 246 rotates at the same speed as the output shaft 19.The sun gear member 242 does not rotate. The planet carrier assemblymember 246, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the ring gear member 244 and the ringgear/sun gear tooth ratio of the planetary gear set 240. The numericalvalue of the third forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 240.

[0097] The fourth forward speed ratio is established with the engagementof the clutches 252 and 254. The clutch 252 connects the planet carrierassembly member 236 to the ring gear member 244. The clutch 254 connectsthe sun gear member 232 to the planet carrier assembly member 246. Theplanet carrier assembly member 226 rotates at the same speed as theinput shaft 17. The ring gear member 224 rotates at the same speed asthe sun gear member 232, the planet carrier assembly member 246, and theoutput shaft 19. The sun gear member 222 rotates at the same speed asthe planet carrier assembly member 236 and the ring gear member 244. Thering gear member 224 rotates at a speed determined from the speed of theplanet carrier assembly member 226, the speed of the sun gear member222, and the ring gear/sun gear tooth ratio of the planetary gear set220. The sun gear member 242 does not rotate. The planet carrierassembly member 246, and therefore the output shaft 19, rotates at aspeed determined from the speed of the ring gear member 244 and the ringgear/sun gear tooth ratio of the planetary gear set 240. The numericalvalue of the fourth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 220 and 240.

[0098] The fifth forward speed ratio is established with the engagementof the clutches 254 and 256. In this configuration, the input shaft 17is directly connected to the output shaft 19. The numerical value of thefifth forward speed ratio is 1.

[0099] The sixth forward speed ratio is established with the engagementof the clutch 254 and the brake 259. The clutch 254 connects the sungear member 232 to the planet carrier assembly member 246. The brake 259connects the ring gear member 234 to the transmission housing 260. Theplanet carrier assembly member 226 rotates at the same speed as theinput shaft 17. The ring gear member 224 rotates at the same speed asthe sun gear member 232, the planet carrier assembly member 246, and theoutput shaft 19. The sun gear member 222 rotates at the same speed asthe planet carrier assembly member 236. The ring gear member 224 rotatesat a speed determined from the speed of the planet carrier assemblymember 226, the speed of the sun gear member 222, and the ring gear/sungear tooth ratio of the planetary gear set 220. The ring gear member 234does not rotate. The planet carrier assembly member 236 rotates at aspeed determined from the speed of the sun gear member 232 and the ringgear/sun gear tooth ratio of the planetary gear set 230. The sun gearmember 242 does not rotate. The numerical value of the sixth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 220 and 230.

[0100] The seventh forward speed ratio is established with theengagement of the clutch 254 and the brake 258. The clutch 254 connectsthe sun gear member 232 to the planet carrier assembly member 246. Thebrake 258 connects the planet carrier assembly member 236 to thetransmission housing 260. The planet carrier assembly member 226 rotatesat the same speed as the input shaft 17. The ring gear member 224rotates at the same speed as the sun gear member 232, the planet carrierassembly member 246, and the output shaft 19. The sun gear members 222and 242 and the planet carrier assembly member 236 do not rotate. Thering gear member 224, and therefore the output shaft 19, rotates at aspeed determined from the speed of the planet carrier assembly member226 and the ring gear/sun gear tooth ratio of the planetary gear set220. The numerical value of the seventh forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 220.

[0101] As previously set forth, the truth table of FIG. 3b describes thecombinations of engagements utilized for the seven forward speed ratiosand reverse ratio. The truth table also provides an example of speedratios that are available with the family member described above. Theseexamples of speed ratios are determined utilizing the tooth ratios givenin FIG. 3b. The R1/S1 value is the tooth ratio of the planetary gear set220; the R2/S2 value is the tooth ratio of the planetary gear set 230;and the R3/S3 value is the tooth ratio of the planetary gear set 240.Also depicted in FIG. 3b is a chart representing the ratio steps betweenadjacent forward speed ratios and the reverse speed ratio. For example,the first to second ratio interchange has a step of 1.7. It can also bereadily determined from the truth table of FIG. 3b that all of thesingle step forward ratio interchanges are of the single transitionvariety.

[0102] A powertrain 310, shown in FIG. 4a, includes the engine andtorque converter 12, a planetary transmission 314, and the final drivemechanism 16. The planetary transmission 314 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 318, and output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 318 includes three planetary gear sets 320, 330 and 340.

[0103] The planetary gear set 320 includes a sun gear member 322, a ringgear member 324, and a planet carrier assembly member 326. The planetcarrier assembly member 326 includes a plurality of pinion gears 327rotatably mounted on a carrier member 329 and disposed in meshingrelationship with both the sun gear member 322 and the ring gear member324.

[0104] The planetary gear set 330 includes a sun gear member 332, a ringgear member 334, and a planet carrier assembly member 336. The planetcarrier assembly member 336 includes a plurality of pinion gears 337rotatably mounted on a carrier member 339 and disposed in meshingrelationship with both the sun gear member 332 and the ring gear member334.

[0105] The planetary gear set 340 includes a sun gear member 342, a ringgear member 344, and a planet carrier assembly member 346. The planetcarrier assembly member 346 includes a plurality of pinion gears 347rotatably mounted on a carrier member 349 and disposed in meshingrelationship with both the sun gear member 342 and the ring gear member344.

[0106] The planetary gear arrangement 318 also includes sixtorque-transmitting mechanisms 350, 352, 354, 356, 358 and 359. Thetorque-transmitting mechanisms 350, 352, 354 and 356 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanisms 358 and 359 are stationary-type torquetransmitting mechanisms, commonly termed brakes or reaction clutches.

[0107] The input shaft 17 is continuously connect with the planetcarrier assembly member 326, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 346. The sun gearmember 342 is continuously connected with the transmission housing 360.The sun gear member 322 is continuously connected with the planetcarrier assembly member 336 through the interconnecting member 370. Theplanet carrier assembly member 326 is continuously connected with thesun gear member 332 through the interconnecting member 372.

[0108] The planet carrier assembly member 336 is selectively connectablewith the sun gear member 332 through the clutch 350. The planet carrierassembly member 336 is selectively connectable with the ring gear member344 through the clutch 352. The ring gear member 324 is selectivelyconnectable with the planet carrier assembly member 346 through theclutch 354. The ring gear member 334 is selectively connectable with theplanet carrier assembly member 346 through the clutch 356. The planetcarrier assembly member 336 is selectively connectable with thetransmission housing 360 through the brake 358. The ring gear member 334is selectively connectable with the transmission housing 360 through thebrake 359.

[0109] The truth tables given in FIGS. 4b, 5 b, 6 b, 7 b, 8 b, 9 b, 10b, 11 b, 12 b and 13 b show the engagement sequences for thetorque-transmitting mechanisms to provide at least seven forward speedratios and at least one reverse ratio. As shown and described above forthe configuration in FIGS. 1a, 2 a and 3 a, those skilled in the artwill understand from the respective truth tables how the speed ratiosare established through the planetary gear sets identified in thewritten description.

[0110] The truth table shown in FIG. 4b describes the engagementcombination and the engagement sequence necessary to provide the reversedrive ratio and seven forward speed ratios. A sample of the numericalvalues for the ratios is also provided in the truth table of FIG. 4b.These values are determined utilizing the ring gear/sun gear toothratios also given in FIG. 4b. The R1/S1 value is the tooth ratio for theplanetary gear set 320; the R2/S2 value is the tooth ratio for theplanetary gear set 330; and the R3/S3 value is the tooth ratio for theplanetary gear set 340. Also given in FIG. 4b is a chart describing thestep ratios between the adjacent forward speed ratios and the reverse tofirst forward speed ratio. For example, the first to second forwardspeed ratio step is 1.72. It can be readily determined from the truthtable of FIG. 4b that each of the forward single step ratio interchangesis a single transition shift, as are the double step interchanges. Thechart also shows that the torque-transmitting mechanism 352 can beengaged through the neutral condition to simplify the forward/reverseinterchange.

[0111] Those skilled in the art will recognize that the numerical valuesof the reverse and seventh forward speed ratios are determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 320. Thenumerical values of the first and second forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 330 and 340. The numerical value of the thirdforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 340. The numerical value of the fourthforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear sets 320 and 340. The numerical value of thefifth forward speed ratio is 1. The numerical value of the sixth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratioof the planetary gear sets 320 and 330. The numerical value of theseventh forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 320.

[0112] A powertrain 410, shown in FIG. 5a, includes the engine andtorque converter 12, a planetary transmission 414 and the final drivemechanism 16. The planetary transmission 414 includes a planetary geararrangement 418, input shaft 17 and output shaft 19. The planetary geararrangement 418 includes three simple planetary gear sets 420, 430 and440.

[0113] The planetary gear set 420 includes a sun gear member 422, a ringgear member 424, and a planet carrier assembly 426. The planet carrierassembly 426 includes a plurality of pinion gears 427 rotatably mountedon a carrier member 429 and disposed in meshing relationship with boththe sun gear member 422 and the ring gear member 424.

[0114] The planetary gear set 430 includes a sun gear member 432, a ringgear member 434, and a planet carrier assembly member 436. The planetcarrier assembly member 436 includes a plurality of pinion gears 437rotatably mounted on a carrier member 439 and disposed in meshingrelationship with both the sun gear member 432 and the ring gear member434.

[0115] The planetary gear set 440 includes a sun gear member 442, a ringgear member 444, and a planet carrier assembly member 446. The planetcarrier assembly member 446 includes a plurality of pinion gears 447rotatably mounted on a carrier member 449 and disposed in meshingrelationship with both the sun gear member 442 and the ring gear member444.

[0116] The planetary gear arrangement 418 also includes sixtorque-transmitting mechanisms 450, 452, 454, 456, 458 and 459. Thetorque-transmitting mechanisms 450, 452, 454, 456 and 458 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 459 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

[0117] The input shaft 17 is continuously connected with the ring gearmember 434, and the output shaft 19 is continuously connected with theplanet carrier assembly member 426. The planet carrier assembly member446 is continuously connected with the transmission housing 460. Thering gear member 424 is continuously connected with the sun gear member432 through the interconnecting member 470. The planet carrier assemblymember 426 is continuously connected with the planet carrier assemblymember 436 through the interconnecting member 472.

[0118] The planet carrier assembly member 436 is selectively connectablewith the ring gear member 444 through the clutch 450. The sun gearmember 432 is selectively connectable with the ring gear member 444through the clutch 452. The sun gear member 432 is selectivelyconnectable with the sun gear member 442 through the clutch 454. The sungear member 422 is selectively connectable with the sun gear member 442through the clutch 456. The ring gear member 434 is selectivelyconnectable with the ring gear member 444 through the clutch 458. Thering gear member 444 is selectively connectable with the transmissionhousing 460 through the brake 459.

[0119] The truth table shown in FIG. 5b describes the engagementcombination and sequence of the torque-transmitting mechanisms 450, 452,454, 456, 458 and 459 that are employed to provide the reverse driveratio and the seven forward speed ratios. It should be noted that thetorque-transmitting mechanism 454 is engaged through the neutralcondition to simplify the forward/reverse interchange.

[0120] Also given in the truth table of FIG. 5b is a set of numericalvalues that are attainable with the present invention utilizing the ringgear/sun gear tooth ratios shown. The R1/S1 value is the tooth ratio ofthe planetary gear set 420; the R2/S2 value is the tooth ratio of theplanetary gear set 430; and the R3/S3 value is the tooth ratio of theplanetary gear set 440. As can also be determined from the truth tableof FIG. 5b, the single step forward interchanges are single transitionshifts.

[0121]FIG. 5b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.84. Those skilled in the art will recognize that the numerical valuesof the first, sixth and seventh forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets420, 430 and 440. The numerical values of the first and second forwardspeed ratios are determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 430 and 440. The numerical value ofthe third forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear set 430. The numerical value ofthe fourth forward speed ratio is 1. The numerical value of the fifthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 420 and 430.

[0122] A powertrain 510, shown in FIG. 6a, includes an engine and torqueconverter 12, a planetary gear transmission 514 and the final drivemechanism 16. The planetary transmission 514 includes the input shaft17, a planetary gear arrangement 518 and the output shaft 19. Theplanetary gear arrangement 518 includes three planetary gear sets 520,530 and 540.

[0123] The planetary gear set 520 includes a sun gear member 522, a ringgear member 524, and a planet carrier assembly 526. The planet carrierassembly 526 includes a plurality of pinion gears 527 rotatably mountedon a carrier member 529 and disposed in meshing relationship with boththe sun gear member 522 and the ring gear member 524.

[0124] The planetary gear set 530 includes a sun gear member 532, a ringgear member 534, and a planet carrier assembly member 536. The planetcarrier assembly member 536 includes a plurality of pinion gears 537rotatably mounted on a carrier member 539 and disposed in meshingrelationship with both the sun gear member 532 and the ring gear member534.

[0125] The planetary gear set 540 includes a sun gear member 542, a ringgear member 544, and a planet carrier assembly member 546. The planetcarrier assembly member 546 includes a plurality of pinion gears 547rotatably mounted on a carrier member 549 and disposed in meshingrelationship with both the sun gear member 542 and the ring gear member544.

[0126] The planetary gear arrangement 518 also includes sixtorque-transmitting mechanisms 550, 552, 554, 556, 558 and 559. Thetorque-transmitting mechanisms 550, 552, 554, 556 and 558 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 559 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

[0127] The input shaft 17 is continuously connected with the ring gearmember 534, and the output shaft 19 is continuously connected with theplanet carrier assembly member 526. The planet carrier assembly member546 is continuously connected with the transmission housing 560. Thering gear member 524 is continuously connected with the sun gear member532 through the interconnecting member 570. The planet carrier assemblymember 526 is continuously connected with the planet carrier assemblymember 536 through the interconnecting member 572.

[0128] The planet carrier assembly member 536 is selectively connectablewith the ring gear member 544 through the clutch 550. The sun gearmember 532 is selectively connectable with the ring gear member 544through the clutch 552. The sun gear member 532 is selectivelyconnectable with the sun gear member 542 through the clutch 554. The sungear member 522 is selectively connectable with the sun gear member 542through the clutch 556. The ring gear member 534 is selectivelyconnectable with the ring gear member 544 through the clutch 558. Thesun gear member 542 is selectively connectable with the transmissionhousing 560 through the brake 559.

[0129] The truth table shown in FIG. 6b describes the engagementsequence and combination of the torque-transmitting mechanisms toprovide the reverse speed ratio and seven forward speed ratios. Itshould be noted that the torque-transmitting mechanism 554 can remainengaged through the neutral condition, thereby simplifying theforward/reverse interchange. It can also be determined from the truthtable of FIG. 6b that all of the single step forward ratio interchangesare of the single transition variety. The chart of FIG. 6b describes theratio steps between adjacent forward speed ratios and the ratio stepbetween the reverse and first forward speed ratio.

[0130] Those skilled in the art, upon reviewing the truth table and theschematic representation of FIG. 6a, can determine that the numericalvalues of the reverse, sixth and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 520, 530 and 540. The numerical values of the firstand second forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 530 and 540. Thenumerical value of the third forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 530. Thenumerical value of the fourth forward speed ratios is 1. The numericalvalue of the fifth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 520 and 530.

[0131] The sample speed ratios given in the truth table are determinedutilizing the tooth ratio values also given in FIG. 6b. The R1/S1 valueis the tooth ratio of the planetary gear set 520; the R2/S2 value is thetooth ratio of the planetary gear set 530; and the R3/S3 value is thetooth ratio of the planetary gear set 540.

[0132] A powertrain 610, shown in FIG. 7a, has the engine and torqueconverter 12, a planetary transmission 614 and the final drive mechanism16. The planetary transmission 614 includes the input shaft 17, aplanetary gear arrangement 618 and the output shaft 19. The planetarygear arrangement 618 includes three planetary gear sets 620, 630 and640.

[0133] The planetary gear set 620 includes a sun gear member 622, a ringgear member 624, and a planet carrier assembly 626. The planet carrierassembly 626 includes a plurality of pinion gears 627 rotatably mountedon a carrier member 629 and disposed in meshing relationship with boththe sun gear member 622 and the ring gear member 624.

[0134] The planetary gear set 630 includes a sun gear member 632, a ringgear member 634, and a planet carrier assembly member 636. The planetcarrier assembly member 636 includes a plurality of pinion gears 637rotatably mounted on a carrier member 639 and disposed in meshingrelationship with both the sun gear member 632 and the ring gear member634.

[0135] The planetary gear set 640 includes a sun gear member 642, a ringgear member 644, and a planet carrier assembly member 646. The planetcarrier assembly member 646 includes a plurality of pinion gears 647rotatably mounted on a carrier member 649 and disposed in meshingrelationship with both the sun gear member 642 and the ring gear member644.

[0136] The planetary gear arrangement 618 also includes sixtorque-transmitting mechanisms 650, 652, 654, 656, 658 and 659. Thetorque-transmitting mechanisms 650, 652, 654 and 656 are of therotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 658 and 659 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

[0137] The input shaft 17 is continuously connected with the sun gearmember 622, and the output shaft 19 is continuously connected with theplanet carrier assembly member 646. The sun gear member 642 iscontinuously connected with the transmission housing 660. The ring gearmember 624 is continuously connected with the ring gear member 634through the interconnecting member 670. The planet carrier assemblymember 626 is continuously connected with the planet carrier assemblymember 636 through the interconnecting member 672.

[0138] The ring gear member 634 is selectively connectable with theplanet carrier assembly member 646 through the clutch 650. The planetcarrier assembly member 636 is selectively connectable with the ringgear member 644 through the clutch 652. The sun gear member 622 isselectively connectable with the sun gear member 632 through the clutch654. The sun gear member 632 is selectively connectable with the planetcarrier assembly member 646 through the clutch 656. The ring gear member634 is selectively connectable with the transmission housing 660 throughbrake 658. The planet carrier assembly member 626 is selectivelyconnectable with the transmission housing 660 through the brake 659.

[0139] The truth table shown in FIG. 7b describes the combination oftorque-transmitting mechanism engagements that will provide the reversedrive ratio and seven forward speed ratios, as well as the sequence ofthese engagements and interchanges. The torque-transmitting mechanism652 can be engaged through the neutral condition, thereby simplifyingthe forward/reverse interchange. It can be noted from the truth tablethat each of the single step forward interchanges are single transitionratio changes.

[0140] The ratio values given are by way of example and are establishedutilizing the ring gear/sun gear tooth ratios given in FIG. 7b. Forexample, the R1/S1 value is the tooth ratio of the planetary gear set620; the R2/S2 value is the tooth ratio of the planetary gear set 630;and the R3/S3 value is the tooth ratio of the planetary gear set 640.The ratio steps between adjacent forward ratios and the reverse to firstratio are also given in FIG. 7b.

[0141] Those skilled in the art will, upon reviewing the truth table ofFIG. 7b, recognize that the numerical value of the reverse speed ratiois determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 620. The numerical values of the first and secondforward speed ratio are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 620 and 640. The numerical valueof the third forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 640. The numericalvalue of the fourth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 620, 630 and 640.The numerical value of the fifth forward speed ratio is 1. The numericalvalues of the sixth and seventh forward speed ratio are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets620 and 630.

[0142] A powertrain 710, shown in FIG. 8a, has the conventional engineand torque converter 12, a planetary transmission 714, and theconventional final drive mechanism 16. The engine and torque converter12 are drivingly connected with the planetary transmission 714 throughthe input shaft 17. The planetary transmission 714 is drivinglyconnected with the final drive mechanism 16 through the output shaft 19.The planetary transmission 714 includes a planetary gear arrangement 718that has a first planetary gear set 720, a second planetary gear set730, and a third planetary gear set 740.

[0143] The planetary gear set 720 includes a sun gear member 722, a ringgear member 724, and a planet carrier assembly 726. The planet carrierassembly 726 includes a plurality of pinion gears 727 rotatably mountedon a carrier member 729 and disposed in meshing relationship with boththe sun gear member 722 and the ring gear member 724.

[0144] The planetary gear set 730 includes a sun gear member 732, a ringgear member 734, and a planet carrier assembly member 736. The planetcarrier assembly member 736 includes a plurality of pinion gears 737rotatably mounted on a carrier member 739 and disposed in meshingrelationship with both the sun gear member 732 and the ring gear member734.

[0145] The planetary gear set 740 includes a sun gear member 742, a ringgear member 744, and a planet carrier assembly member 746. The planetcarrier assembly member 746 includes a plurality of pinion gears 747 and748 rotatably mounted on a carrier member 749 and disposed in meshingrelationship with both the sun gear member 742 and the ring gear member744.

[0146] The planetary gear arrangement 718 also includes sixtorque-transmitting mechanisms 750, 752, 754, 756, 758 and 759, each ofwhich is a rotating-type torque-transmitting mechanism, commonly termedclutch.

[0147] The input shaft 17 is continuously connected with the ring gearmember 734, and the output shaft 19 is continuously connected with theplanet carrier assembly member 726. The ring gear member 744 iscontinuously connected with the transmission housing 760. The planetcarrier assembly member 726 is continuously connected with the planetcarrier assembly member 736 through the interconnecting member 770. Thering gear member 724 is continuously connected with the sun gear member732 through the interconnecting member 772.

[0148] The planet carrier assembly member 736 is selectively connectablewith the planet carrier assembly member 746 through the clutch 750. Thesun gear member 732 is selectively connectable with the planet carrierassembly member 746 through the clutch 752. The sun gear member 732 isselectively connectable with the sun gear member 742 through the clutch754. The sun gear member 722 is selectively connectable with the sungear member 742 through the clutch 756. The ring gear member 734 isselectively connectable with the planet carrier assembly member 746through the clutch 758. The planet carrier assembly member 746 isselectively connectable with the sun gear member 742 through the clutch759.

[0149] The truth table of FIG. 8b defines the torque-transmittingmechanism engagement sequence utilized for each of the forward speedratios and the reverse speed ratio. Also given in the truth table is aset of numerical values that are attainable with the present inventionutilizing the ring gear/sun gear tooth ratios given in FIG. 8b. TheR1/S1 value is the tooth ratio of the planetary gear set 720; the R2/S2value is the tooth ratio of the planetary gear set 730; and the R3/S3value is the tooth ratio of the planetary gear set 740. As can also bedetermined from the truth table of FIG. 8b, the single step forwardinterchanges are single transition shifts.

[0150]FIG. 8b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.84. Those skilled in the art will recognize that the numerical valuesof the reverse, sixth and seventh forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets720, 730 and 740. The numerical values of the first and second forwardspeed ratios are determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 730 and 740. The numerical value ofthe third forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 730. The numerical value ofthe fourth forward speed ratio is 1. The numerical value of the fifthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 720 and 730.

[0151] A powertrain 810, shown in FIG. 9a, has the conventional engineand torque converter 12, a planetary transmission 814, and the finaldrive mechanism 16. The engine and torque converter 12 are drivinglyconnected with the planetary transmission 814 through the input shaft17. The planetary transmission 814 is drivingly connected with the finaldrive mechanism 16 through the output shaft 19. The planetarytransmission 814 includes a planetary gear arrangement 818 that has afirst planetary gear set 820, a second planetary gear set 830, and athird planetary gear set 840.

[0152] The planetary gear set 820 includes a sun gear member 822, a ringgear member 824, and a planet carrier assembly 826. The planet carrierassembly 826 includes a plurality of pinion gears 827 rotatably mountedon a carrier member 829 and disposed in meshing relationship with boththe sun gear member 822 and the ring gear member 824.

[0153] The planetary gear set 830 includes a sun gear member 832, a ringgear member 834, and a planet carrier assembly member 836. The planetcarrier assembly member 836 includes a plurality of pinion gears 837rotatably mounted on a carrier member 839 and disposed in meshingrelationship with both the sun gear member 832 and the ring gear member834.

[0154] The planetary gear set 840 includes a sun gear member 842, a ringgear member 844, and a planet carrier assembly member 846. The planetcarrier assembly member 846 includes a plurality of pinion gears 847rotatably mounted on a carrier member 849 and disposed in meshingrelationship with both the sun gear member 842 and the ring gear member844.

[0155] The planetary gear arrangement 818 also includes sixtorque-transmitting mechanisms 850, 852, 854, 856, 858 and 859. Thetorque-transmitting mechanisms 850, 852, 854 and 856 are of therotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 858 and 859 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

[0156] The input shaft 17 is continuously connected with the planetcarrier assembly member 846, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 826. The ring gearmember 844 is continuously connected with the transmission housing 860.The planet carrier assembly member 826 is continuously connected withthe ring gear member 834 through the interconnecting member 870. Thering gear member 824 is continuously connected with the planet carrierassembly member 836 through the interconnecting member 872.

[0157] The planet carrier assembly member 836 is selectively connectablewith the sun gear member 842 through the clutch 850. The sun gear member822 is selectively connectable with the planet carrier assembly member846 through the clutch 852. The sun gear member 832 is selectivelyconnectable with the sun gear member 842 through the clutch 854. The sungear member 832 is selectively connectable with the planet carrierassembly member 846 through the clutch 856. The ring gear member 824 isselectively connectable with the transmission housing 860 through thebrake 858. The sun gear member 832 is selectively connectable with thetransmission housing 860 through the brake 859.

[0158] The truth table shown in FIG. 9b defines the torque-transmittingmechanism engagement sequence that provides two reverse speed ratios andeight forward speed ratios shown in the truth table and available withthe planetary gear arrangement 818. The truth table indicates that thetorque-transmitting mechanism 858 can remain engaged through the neutralcondition, thereby simplifying the forward/reverse interchange. A sampleof numerical values for the individual ratios is also given in the truthtable of FIG. 9b. These numerical values have been calculated using thering gear/sun gear tooth ratios also given by way of example in FIG. 9b.The R1/S1 value is the tooth ratio of the planetary gear set 820; theR2/S2 value is the tooth ratio of the planetary gear set 830; and theR3/S3 value is the tooth ratio of the planetary gear set 840. It can bereadily recognized from the truth table that all of the single anddouble step forward interchanges are single transition ratiointerchanges. FIG. 9b also describes the ratio steps between adjacentforward ratios and between the reverse (Reverse#2) and first forwardratio. For example, the ratio step between the first and second forwardratios is 1.77.

[0159] Those skilled in the art of planetary transmissions willrecognize that the numerical value of the reverse speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 830. The numerical value of the first forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 820. The numerical value of the second forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 820 and 830. The numerical value of the thirdforward speed ratio is 1. The numerical value of the fourth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 820, 830 and 840. The numerical value of thefifth forward speed ratio is determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 820 and 840. The numerical valueof the sixth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 840. The numericalvalues of the seventh and eighth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets830 and 840.

[0160] The powertrain 910, shown in FIG. 10a, includes the conventionalengine and torque converter 12, a planetary transmission 914, and theconventional final drive mechanism 16. The engine and torque converter12 are drivingly connected with the planetary transmission 914 throughthe input shaft 17. The planetary transmission 914 is drivinglyconnected with the final drive mechanism 16 through the output shaft 19.The planetary transmission 914 includes a planetary gear arrangement 918that has a first planetary gear set 920, a second planetary gear set930, and a third planetary gear set 940.

[0161] The planetary gear set 920 includes a sun gear member 922, a ringgear member 924, and a planet carrier assembly 926. The planet carrierassembly 926 includes a plurality of pinion gears 927 that are rotatablymounted on a carrier member 929 and disposed in meshing relationshipwith the sun gear member 922 and the ring gear member 924, respectively.

[0162] The planetary gear set 930 includes a sun gear member 932, a ringgear member 934, and a planet carrier assembly member 936. The planetcarrier assembly member 936 includes a plurality of pinion gears 937rotatably mounted on a carrier member 939 and disposed in meshingrelationship with both the sun gear member 932 and the ring gear member934.

[0163] The planetary gear set 940 includes a sun gear member 942, a ringgear member 944, and a planet carrier assembly member 946. The planetcarrier assembly member 946 includes a plurality of pinion gears 947rotatably mounted on a carrier member 949 and disposed in meshingrelationship with both the sun gear member 942 and the ring gear member944.

[0164] The planetary gear arrangement 918 also includes sixtorque-transmitting mechanisms 950, 952, 954, 956, 958 and 959. Thetorque-transmitting mechanisms 950, 952, 954 and 956 are rotating-typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanisms 958 and 959 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

[0165] The input shaft 17 is continuously connected with the planetcarrier assembly member 946, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 926. The ring gearmember 944 is continuously connected with the transmission housing 960.The ring gear member 924 is continuously connected with the planetcarrier assembly member 936 through the interconnecting member 970. Thesun gear member 922 is continuously connected with the sun gear member932 through the interconnecting member 972.

[0166] The sun gear member 922 is selectively connectable with theplanet carrier assembly member 936 through the clutch 950. The planetcarrier assembly member 936 is selectively connectable with the sun gearmember 942 through the clutch 952. The sun gear member 932 isselectively connectable with the planet carrier assembly member 946through the clutch 954. The ring gear member 934 is selectivelyconnectable with the planet carrier assembly member 946 through theclutch 956. The ring gear member 924 is selectively connectable with thetransmission housing 960 through the brake 958. The ring gear member 934is selectively connectable with the transmission housing 960 through thebrake 959.

[0167] The truth table of FIG. 10b describes the torque-transmittingmechanism engagement sequence utilized to provide the reverse speedratio and seven forward speed ratios. The truth table also provides aset of examples for the ratios for each of the reverse and forward speedratios. These numerical values have been determined utilizing the ringgear/sun gear tooth ratios given in FIG. 10b. The R1/S1 value is thetooth ratio of the planetary gear set 920; the R2/S2 value is the toothratio of the planetary gear set 930; and the R3/S3 value is the toothratio of the planetary gear set 940. It can also be determined from thetruth table of FIG. 10b that each of the forward single step ratiointerchanges are of the single transition variety.

[0168] Those skilled in the art, upon reviewing the engagementcombinations, will recognize that the numerical values of the reverseand second forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 920 and 930. Thenumerical value of the first forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 920. Thenumerical value of the third forward speed ratio is 1. The numericalvalue of the fourth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 920 and 940. Thenumerical value of the fifth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear sets 940. Thenumerical values of the sixth and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 920, 930 and 940.

[0169] A powertrain 1010, shown in FIG. 11a, includes the conventionalengine and torque converter 12, a planetary transmission 1014, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1014 through theinput shaft 17. The planetary transmission 1014 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1014 includes a planetary gear arrangement 1018that has a first planetary gear set 1020, a second planetary gear set1030, and a third planetary gear set 1040.

[0170] The planetary gear set 1020 includes a sun gear member 1022, aring gear member 1024, and a planet carrier assembly 1026. The planetcarrier assembly 1026 includes a plurality of pinion gears 1027rotatably mounted on a carrier member 1029 and disposed in meshingrelationship with both the sun gear member 1022 and the ring gear member1024.

[0171] The planetary gear set 1030 includes a sun gear member 1032, aring gear member 1034, and a planet carrier assembly member 1036. Theplanet carrier assembly member 1036 includes a plurality of pinion gears1037 rotatably mounted on a carrier member 1039 and disposed in meshingrelationship with both the sun gear member 1032 and the ring gear member1034.

[0172] The planetary gear set 1040 includes a sun gear member 1042, aring gear member 1044, and a planet carrier assembly member 1046. Theplanet carrier assembly member 1046 includes a plurality of pinion gears1047 rotatably mounted on a carrier member 1049 and disposed in meshingrelationship with both the sun gear member 1042 and the ring gear member1044.

[0173] The planetary gear arrangement 1018 also includes sixtorque-transmitting mechanisms 1050, 1052, 1054, 1056, 1058 and 1059.The torque-transmitting mechanisms 1050, 1052, 1054 and 1056 are of therotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1058 and 1059 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

[0174] The input shaft 17 is continuously connected with the sun gearmember 1042, and the output shaft 19 is continuously connected with theplanet carrier assembly member 1036. The planet carrier assembly member1046 is continuously connected with the transmission housing 1060. Theplanet carrier assembly member 1026 is continuously connected with thering gear member 1034 through the interconnecting member 1070. The ringgear member 1024 is continuously connected with the planet carrierassembly member 1036 through the interconnecting member 1072.

[0175] The ring gear member 1034 is selectively connectable with the sungear member 1042 through the clutch 1050. The ring gear member 1034 isselectively connectable with the ring gear member 1044 through theclutch 1052. The sun gear member 1022 is selectively connectable withthe ring gear member 1044 through the clutch 1054. The sun gear member1032 is selectively connectable with the sun gear member 1042 throughthe clutch 1056. The planet carrier assembly member 1026 is selectivelyconnectable with the transmission housing 1060 through the brake 1058.The sun gear member 1022 is selectively connectable with thetransmission housing 1060 through the brake 1059.

[0176] The truth table shown in FIG. 11b describes the engagementcombinations and the engagement sequence necessary to provide thereverse drive ratio and the seven forward speed ratios. A sample of thenumerical values for the ratios is also provided in the truth table ofFIG. 11b. These values are determined utilizing the ring gear/sun geartooth ratios also given in FIG. 11b. The R1/S1 value is the tooth ratiofor the planetary gear set 1020; the R2/S2 value is the tooth ratio forthe planetary gear set 1030; and the R3/S3 value is the tooth ratio forthe planetary gear set 1040. Also given in FIG. 11b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

[0177] Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1040. The numerical values ofthe first and third forward-speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 1020, 1030and 1040. The numerical value of the second forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 1030. The numerical value of the fourth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1020 and 1030. The numerical value of the fifthforward speed ratio is 1. The numerical value of the sixth forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 1020. The numerical value of the seventh forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 1020 and 1040.

[0178] A powertrain 1110, shown in FIG. 12a, has a conventional engineand torque converter 12, a planetary transmission 1114, and theconventional final drive mechanism 16. The planetary transmission 1114includes a planetary gear arrangement 1118 which is connected with theengine and torque converter 12 through the input shaft 17 and with thefinal drive mechanism 16 through the output shaft 19. The planetary geararrangement 1118 includes three planetary gear sets 1120, 1130 and 1140.

[0179] The planetary gear set 1120 includes a sun gear member 1122, aring gear member 1124, and a planet carrier assembly 1126. The planetcarrier assembly 1126 includes a plurality of pinion gears 1127rotatably mounted on a carrier member 1129 and disposed in meshingrelationship with both the sun gear member 1122 and the ring gear member1124.

[0180] The planetary gear set 1130 includes a sun gear member 1132, aring gear member 1134, and a planet carrier assembly member 1136. Theplanet carrier assembly member 1136 includes a plurality of intermeshingpinion gears 1137 that are rotatably mounted on a carrier member 1139and disposed in meshing relationship with both the sun gear member 1132and the ring gear member 1134.

[0181] The planetary gear set 1140 includes a sun gear member 1142, aring gear member 1144, and a planet carrier assembly member 1146. Theplanet carrier assembly member 1146 includes a plurality of pinion gears1147 rotatably mounted on a carrier member 1149 and disposed in meshingrelationship with both the sun gear member 1142 and the ring gear member1144.

[0182] The planetary gear arrangement 1118 also includes sixtorque-transmitting mechanisms 1150, 1152, 1154, 1156, 1158 and 1159.The torque-transmitting mechanisms 1150, 1152, 1154 and 1156 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1158 and 1159 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

[0183] The input shaft 17 is continuously connected with the ring gearmember 1144, and the output shaft 19 is continuously connected with thering gear member 1124. The sun gear member 1142 is continuouslyconnected with the transmission housing 1160. The sun gear member 1122is continuously connected with the ring gear member 1134 through theinterconnecting member 1170. The planet carrier assembly member 1126 iscontinuously connected with the planet carrier assembly member 1136through the interconnecting member 1172.

[0184] The ring gear member 1124 is selectively connectable with theplanet carrier assembly member 1126 through the clutch 1150. The planetcarrier assembly member 1136 is selectively connectable with the ringgear member 1144 through the clutch 1152. The ring gear member 1134 isselectively connectable with the planet carrier assembly member 1146through the clutch 1154. The sun gear member 1132 is selectivelyconnectable with the planet carrier assembly member 1146 through theclutch 1156. The planet carrier assembly member 1126 is selectivelyconnectable with the transmission housing 1160 through the brake 1158.The ring gear member 1134 is selectively connectable with thetransmission housing 1160 through the brake 1159.

[0185] The truth table shown in FIG. 12b describes the engagementsequence and engagement combinations utilized with the present familymember to provide the reverse drive ratio and seven forward speedratios. The truth table of FIG. 12b also provides a set of examplenumbers that can be established in the planetary gear arrangement 1118utilizing the ring gear/sun gear tooth ratios. The R1/S1 value is thering gear/sun gear tooth ratio of the planetary gear set 1120; the R2/S2value is the ring gear/sun gear tooth ratio of the planetary gear set1130; and the R3/S3 value is the ring gear/sun gear tooth ratio of theplanetary gear set 1140.

[0186] The chart of FIG. 12b describes the ratio steps between adjacentforward speed ratios for a seven-speed transmission. These step ratiosare established utilizing the example speed ratios given in the truthtable. As also shown in the truth table, the torque-transmittingmechanism 1158 can remain engaged through the neutral condition, therebysimplifying the forward/reverse interchange.

[0187] Those skilled in the art will recognize that the numerical valuesof the reverse and sixth forward speed ratios are determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear set 1120 and1140. The numerical values of the first, second and fourth forward speedratios are determined utilizing the ring gear/sun gear tooth ratios ofthe planetary gear sets 1120, 1130 and 1140. The numerical value of thethird forward speed ratio is determined utilizing the ring gear/sun geartooth ratio of the planetary gear set 1140. The numerical value of thefifth forward speed ratio is 1. The numerical value of the seventhforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1120.

[0188] A powertrain 1210, shown in FIG. 13a, includes the conventionalengine and torque converter 12, a planetary transmission 1214, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1214 through theinput shaft 17. The planetary transmission 1214 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1214 includes a planetary gear arrangement 1218that has a first planetary gear set 1220, a second planetary gear set1230, and a third planetary gear set 1240.

[0189] The planetary gear set 1220 includes a sun gear member 1222, aring gear member 1224, and a planet carrier assembly 1226. The planetcarrier assembly 1226 includes a plurality of pinion gears 1227rotatably mounted on a carrier member 1229 and disposed in meshingrelationship with both the sun gear member 1222 and the ring gear member1224.

[0190] The planetary gear set 1230 includes a sun gear member 1232, aring gear member 1234, and a planet carrier assembly member 1236. Theplanet carrier assembly member 1236 includes a plurality of pinion gears1237 rotatably mounted on a carrier member 1239 and disposed in meshingrelationship with both the sun gear member 1232 and the ring gear member1234.

[0191] The planetary gear set 1240 includes a sun gear member 1242, aring gear member 1244, and a planet carrier assembly member 1246. Theplanet carrier assembly member 1246 includes a plurality of pinion gears1247 rotatably mounted on a carrier member 1249 and disposed in meshingrelationship with both the sun gear member 1242 and the ring gear member1244.

[0192] The planetary gear arrangement 1218 also includes six torquetransmitting mechanisms 1250, 1252, 1254, 1256, 1258 and 1259. Thetorque-transmitting mechanisms 1250, 1252, 1254 and 1256 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1258 and 1259 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

[0193] The input shaft 17 is continuously connected with the planetcarrier assembly member 1246, and the output shaft 19 is continuouslyconnected with the planet carrier assembly member 1236. The ring gearmember 1244 is continuously connected with the transmission housing1260. The planet carrier assembly member 1226 is continuously connectedwith the ring gear member 1234 through the interconnecting member 1270.The ring gear member 1224 is continuously connected with the planetcarrier assembly member 1236 through the interconnecting member 1272.

[0194] The ring gear member 1234 is selectively connectable with the sungear member 1242 through the clutch 1250. The sun gear member 1222 isselectively connectable with the planet carrier assembly member 1246through the clutch 1252. The sun gear member 1222 is selectivelyconnectable with the sun gear member 1242 through the clutch 1254. Thesun gear member 1232 is selectively connectable with the planet carrierassembly member 1246 through the clutch 1256. The planet carrierassembly member 1226 is selectively connectable with the transmissionhousing 1260 through the brake 1258. The sun gear member 1222 isselectively connectable with the transmission housing 1260 through thebrake 1259.

[0195] The truth table shown in FIG. 13b describes the engagementcombinations and the engagement sequence necessary to provide tworeverse speed ratios and eight forward speed ratios. A sample of thenumerical values for the ratios is also provided in the truth table ofFIG. 13b. These values are determined utilizing the ring gear/sun geartooth ratios also given in FIG. 13b. The R1/S1 value is the tooth ratiofor the planetary gear set 1220; the R2/S2 value is the tooth ratio forthe planetary gear set 1230; and the R3/S3 value is the tooth ratio forthe planetary gear set 1240. Also given in FIG. 13b is a chartdescribing the step ratios between the adjacent forward speed ratios andthe reverse to first forward speed ratio.

[0196] Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1220. The numerical value ofthe first forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1230. The numerical value ofthe second forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1220 and 1230. Thenumerical value of the third forward speed ratio is 1. The numericalvalue of the fourth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1220, 1230 and1240. The numerical value of the fifth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1230 and 1240. The numerical value of the sixth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 1240. The numerical values of the seventh and eighth forwardspeed ratios are determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1220 and 1240.

[0197] While the best modes for carrying out the invention have beendescribed in detail, those familiar with the art to which this inventionrelates will recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

1. A family of transmissions wherein each family member comprises: aninput shaft; an output shaft; first, second and third planetary gearsets each having first, second and third members; said input shaft beingcontinuously interconnected with a member of said planetary gear sets,and said output shaft being continuously interconnected with anothermember of said planetary gear sets; a first interconnecting membercontinuously interconnecting said first member of said first planetarygear set and said first member of said second planetary gear set; asecond interconnecting member continuously interconnecting said secondmember of said first planetary gear set with said second member of saidsecond planetary gear set; said first member of said third planetarygear set being continuously connected with a transmission housing; afirst torque-transmitting mechanism selectively interconnecting a memberof said first planetary gear set with said input shaft, said outputshaft, or a member of said second or third planetary gear set; a secondtorque-transmitting mechanism selectively interconnecting a member ofsaid second planetary gear set with said input shaft, said output shaft,or a member of said first or third planetary gear set; a thirdtorque-transmitting mechanism selectively interconnecting a member ofsaid third planetary gear set with said input shaft, said output shaft,or a member of said first or second planetary gear set; a fourthtorque-transmitting mechanism selectively interconnecting a member ofsaid first, second or third planetary gear set with another member ofsaid first, second or third planetary gear set; a fifthtorque-transmitting mechanism selectively interconnecting a member ofsaid first, second or third planetary gear set with another member ofsaid first or second planetary gear set or with said transmissionhousing; and a sixth torque-transmitting mechanism selectivelyinterconnecting a member of the first, second or third planetary gearset with another member of said first, second or third planetary gearset, said first or second interconnecting member, or with saidtransmission housing; said torque-transmitting mechanisms being engagedin combinations of two to establish at least seven forward speed ratiosand at least one reverse speed ratio between said input shaft and saidoutput shaft.
 2. The family of transmissions defined in claim 1, whereinsaid first, second, third, fourth, fifth and sixth torque-transmittingmechanisms comprise clutches.
 3. The family of transmissions defined inclaim 1, wherein said first, second, third, fourth and fifthtransmitting mechanisms comprise clutches, and said sixthtorque-transmitting mechanism comprises a brake.
 4. The family oftransmissions defined in claim 1, wherein said first, second, third andfourth torque-transmitting mechanisms comprise clutches, and said fifthand sixth torque-transmitting mechanisms comprise brakes.
 5. The familyof transmissions defined in claim 1, wherein planet carrier assemblymembers of each of said planetary gear sets are of the single-piniontype.
 6. The family of transmissions defined in claim 1, wherein atleast one planet carrier assembly member of said planetary gear sets isof the double-pinion type.
 7. A family of transmissions having aplurality of family members wherein each family member comprises: aninput shaft; an output shaft; a planetary gear arrangement having first,second and third planetary gear sets, each planetary gear set havingfirst, second and third members; said input shaft being continuouslyinterconnected with a member of said planetary gear sets, and saidoutput shaft being continuously interconnected with another member ofsaid planetary gear sets; a first interconnecting member continuouslyinterconnecting said first member of said first planetary gear set andsaid first member of said second planetary gear set; a secondinterconnecting member continuously interconnecting said second memberof said first planetary gear set with said second member of said secondplanetary gear set; said first member of said third planetary gear setbeing continuously connected with a transmission housing; and sixtorque-transmitting mechanisms for selectively interconnecting saidmembers of said first, second or third planetary gear sets with saidinput shaft, said output shaft, said first or second interconnectingmembers, said transmission housing or with other members of saidplanetary gear sets, said six torque-transmitting mechanisms beingengaged in combinations of two to establish at least seven forward speedratios and at least one reverse speed ratio between said input shaft andsaid output shaft.
 8. The family of transmissions defined in claim 7,wherein a first of said six torque-transmitting mechanisms is operablefor selectively interconnecting a member of said first planetary gearset with said input shaft, said output shaft, or a member of said secondor third planetary gear set.
 9. The family of transmissions defined inclaim 7, wherein a second of said six torque-transmitting mechanisms isoperable for selectively interconnecting a member of said secondplanetary gear set with said input shaft, said output shaft, or a memberof said first or third planetary gear set.
 10. The family oftransmissions defined in claim 7, wherein a third of said sixtorque-transmitting mechanisms is selectively operable forinterconnecting a member of said third planetary gear set with saidinput shaft, said output shaft, or a member of said first or secondplanetary gear set.
 11. The family of transmissions defined in claim 7,wherein a fourth of said six torque-transmitting mechanisms isselectively operable for interconnecting a member of said first, secondor third planetary gear set with another member of said first, second orthird planetary gear set.
 12. The family of transmissions defined inclaim 7, wherein a fifth of said six torque-transmitting mechanisms isselectively operable for interconnecting a member of said first, secondor third planetary gear set with another member of said second or thirdplanetary gear set or with said transmission housing.
 13. The family oftransmissions defined in claim 7, wherein a sixth of said sixtorque-transmitting mechanisms selectively interconnects a member ofsaid first, second or third planetary gear set with another member ofsaid first, second or third planetary gear set, said first or secondinterconnecting member, or with said transmission housing.
 14. Thefamily of transmissions defined in claim 7, wherein planet carrierassembly members of each of said planetary gear sets are of thesingle-pinion type.
 15. The family of transmissions in claim 7, whereinat least one planet carrier assembly member of said planetary gear setsis of the double-pinion type.